<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>侧滑菜单示例</title>
    <style>
        * {margin: 0; padding: 0; box-sizing: border-box;}
        body {
            background-color: skyblue;
        }
        .menu-wrapper {
            position: fixed;
            left: -238px;
            top: 0;
            width: 250px;
            height: 100%;
            background-color: red;
            padding-right: 12px;
            transition: all .4s ease-in;
        }
        .menu-wrapper:hover {
            left: 0px;
        }
        .menu-inner {
            width: 100%;
            height: 100%;
            background-color: blue;
        }
    </style>
</head>
<body>
    <div class="menu-wrapper">
        <div class="menu-inner"></div>
    </div>
</body>
</html>